Lachlan, I have no idea. A replenisher formula is a very complex equation that tries to account for silver level coated and halide level. It must thus work with a lot of films. Such a math formula might be publishes somewhere, but I don't have one.
Sorry.
PE
Such agents are now used in emulsion making. That is why modern emulsions are much more resistant to dichroic fog.
The formula I posted above was straight from Dick. That is all I can say. It was about 50 years ago after all. He may have said something like this: Here is the formula (which I wrote down) and then he might have added - of course, you know there is some Sodium Chloride in there. Everyone knows that.
Of course I don't remember. I remember him saying that ultra high Sulfite levels along with the 4 chloro-resorcinol was used.
PE[/QUOTE
So, if I'm understanding you right, PE, since the agents for fighting dichroic fog are now a part of the film emulsion, wouldn't the non-X version of Microdol work with modern films?
So, if I'm understanding you right, PE, since the agents for fighting dichroic fog are now a part of the film emulsion, wouldn't the non-X version of Microdol work with modern films?
Consider the 1l packs and tins and you'll notice that the net weight isn't always the same. I've seen 132 and 135g. Now, consider the 1US gal packs and divide their net weight (482g) by 3,8. This gives you ~127g. That's enough of a headache. It seems that the Microdol-X formula wasn't always the same. Some tweaks have probably been made, maybe because a chelating agent was substituted with another. But in any case, the substitute formula lists 100g sulfite, 5g Metol and 30g sodium chloride, for a total of 135g. Not too far away eh?... As for the Sodium Sulfite amount would it not be prudent to examine a Kodak branded bag of Microdol-X and note the listed weight? Perhaps we may extrapolate from there....
While it is true that metol, SS and good old pickling salt will do the trick just as well, my interest was in what made Microdol-X impart a brownish tone to my negatives. I've wasted more time on a bar stool and got nothing in return but a headache and an empty wallet. This waste of time really cost me nothing. JohnWSo, if we've making up our developer with distilled water like you're supposed to, all you need is Metol, sodium sulfite, and salt.... The sodium citrate is only there to keep the calcium in hard water from becoming a problem, so if you use distilled water, you don't need it.
Well, crap !
I wonder how many man hours have been wasted by people trying to figure out the formula for Microdol-X when the adding of the anti-dichroic fog agent to the film's emulsion solved the dichroic fog problem sometime back and nobody knew about it.
I don't think so. I have used the homebrew version with several films and TMax 100 in particular got a brownish tone, especially noticeable in mid to high densities. The exposed leader has a definite brown tone, so much so that seeing this alone could fool someone in believing that it was developed in something like Pyrocat. I also have a suspicion that this brown tone is lessened with overdevelopment, something that would make sense IMHO.Is there sound evidence, that a fresh batch of Microdol-X would create negatives with brown tone, and Metol/SS/NaCl homebrew version would not?
The brown tone is a result of the grain size. I have experienced the same with an ascorbate developer so it s not a result of a particular chemical.
If you look at the claims of this patent, only two developer formulas are actually claimed as invention, and these two formulas are nothing like Microdol or Microdol-X.
I agree that some ideas of this patent may have been used later by the same inventors, but not in Microdol. However, what is your objection to their Example 5 being Microdol?You have to differentiate between the patent body and the list of claims. A patent can state all kinds of stuff, but the only thing really protected by that patent is the list of claims, and in this case this covers these two developer formulas at the end. Microdol was never covered by this patent, but the patent itself (which counts as publication on its own) may have excluded other people from later patenting crucial aspects of Microdol (e.g. the NaCl). It could have been just a defensive patent, or maybe Henn&Crabtree really thought of commercializing the two claimed formulas before they discovered Microdol. Who knows?
Well. I beg to differ. The formulas in the patent are all claimed to give reduction of grain. Most are basically D-23 with alkali metal chloride salt added AND a primary amine...
Well, for whatever it is worth, I just finished a little experiment with a metol-based concoction and Kentmere 100. The concoction was the following (per liter): metol 8 g, sodium sulfite 2 g, sodium citrate 44 g. NO chloride. I added citrate until the pH of this concoction was 7. I then left it for a month in a tightly closed vessel with very little air, to see how fast it would display any sign of oxidation. As there was none, I developed a few clips to determine the time. It turned out to be 70 minutes (yes, seventy) at 20 degrees Celsius. I only agitated it once every 10 minutes. However, I was rewarded with a soft negative that was very fine grained. I would not bet (without a microscope) that it was better than in the "Microdol homebrew", but it confirms my idea that at least for this film and metol the low pH is the essential factor for fine grain. Obviously, I went a little too far with the pH, and maintaining it in the narrow range between 7.7 and 7.9 is a compromise between development speed being within practical limits and fineness of grain, as produced by metol. This little experiment also provides an indirect hint as to why some people like D-23 and some don't, as depending on the purity of sulfite they may actually have different developers in their hands. Likewise, since a lay person has no means of adjusting pH with this level of precision, it means your outcome may vary also with the "homebrew Microdol" depending on the actual quality of chemicals used. Trying to use it with replenishment is asking for further trouble and may eventually completely defeat the purpose. It may "work" but there are definitely better developers out there.An older version of the Microdol-X msds lists more ingredients than the latest version, and these are:
70-75% Sodium sulfite (007757-83-7)
20-25% Sodium chloride (007647-14-5)
1-5% 4-(methylamino)phenol sulfate (000055-55-0)
< 1% Boric anhydride (001303-86-2)
< 1% Sodium hexametaphosphate (010124-56-8)
It doesn't mention any amine in any significant quantity. All of the patent's formulae have significant amounts of amines and would have been listed in such an msds, so this excludes example 5 of the patent from being the true MIcrodol-X formula. Apart from that, the msds lists the working solution's pH in the range of 7,7 to 7,9. If you mix the typical homebrew formula*, you will end up in this pH range (~7,8). IMHO, people get too carried away trying to find the exact Microdol-X formula, when the homebrew one works just fine.
* 100g sodium sulfite, 5g Metol, 30g NaCl
Yes, sort of. In my perception D-25 was constructed to lower the pH of D-23, which action in itself results in a finer grain, with a lot of sulfite acting as a buffer and a halide solvent. To isolate the effect of low pH, I did make another buffer, titrating metol with sodium citrate, but lowered sulfite to a minimum. At this point I am not going to try this concoction on all films currently on the market.Pixophrenic, did you just reinvent some sort of complicated version of D-25 ? Any reason for using so little sulfite?
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